电针预处理对心肌缺血再灌注损伤大鼠“内关”穴区Toll样受体4、髓样分化因子88及核转录因子-κB基因表达的影响

Effect of Electroacupuncture Preconditioning on Myocardial Ischemia and Expression of TLR 4,MyD 88and NF-κB mRNAs in“Neiguan”(PC 6)Area in Rats with Myocardial Ischemia-reperfusion Injury

目的:观察电针预处理对心肌缺血再灌注损伤(MIRI)大鼠"内关"穴区Toll样受体4(TLR 4)、髓样分化因子88(MyD 88)以及核转录因子-κB(NF-κB)mRNA表达的影响,探讨"内关"抗心肌缺血再灌注的作用与TLR 4/MyD 88/NF-κB信号通路的关系。方法:Wistar大鼠随机分成正常组、正常电针组、假手术组、模型组、电针组和假电针组,每组8只。采用左冠状动脉前降支结扎法制备MIRI大鼠模型,造模前5d开始电针预处理,电针组、正常电针组、假电针组针刺"内关"穴,并给予相应的电针干预,每次30min,每日1次,连续5d。Real-time PCR法检测大鼠"内关"穴区TLR 4、MyD 88和NF-κB mRNA表达水平。结果:与正常组比较,模型组心电图(ECG)-J点显著升高(P<0.01),电针组与模型组和假电针组相比,ECG-J点高度降低(P<0.01)。与正常组相比,模型组大鼠"内关"穴区TLR 4、MyD 88和NF-κB mRNA表达水平显著升高(P<0.01);电针组与模型组、假电针组相比,"内关"穴区TLR 4、MyD 88和NF-κB mRNA的表达水平降低(P<0.05)。结论:电针预处理能降低MIRI大鼠"内关"穴区TLR 4、MyD 88和NF-κB mRNA的表达水平,因此针刺信号的启动-传递-放大可能与TLR 4/MyD 88/NF-κB信号通路有关。

Objective To observe the effect of electroacupuncture（EA）preconditioning on acute myocardial ischemia（MI）and expression of Toll-like receptor 4（TLR 4）,myeloid differentiation factor 88（MyD 88）and nuclear factor-κB（NF-κB）mRNAs in the＂Neiguan＂（PC 6）area of rats with MI-reperfusion injury（MIRI）,so as to explore its mechanisms underlying improvement of MIRI.Methods Forty-eight male Wistar rats were randomly divided into control,control＋ EA,sham operation,model,EA and sham EA groups（n=8）.The MIRI model was established by occlusion of the descending anterior branch of the left coronary artery for 30 min,followed by reperfusion.Before modeling,EA preconditioning was respectively applied to PC 6 or sham PC 6 for 30 min,once daily for 5 days.Electrocardiogram（ECG）of the standard limb-leadⅡ was recorded before and after the modeling,and 0.25 hafter reperfusion.The expression levels of TLR 4,MyD 88 and NF-κB genes in the PC 6 tissue were detected by Real-time PCR.Results Compared with the control group,the height of ECG J-point was significantly increased in the model group（P〈0.01）,suggesting an acute MI,and the height of J-point was significantly lower in the EA group than in the model and sham EA groups（P〈0.01）.In comparison with the control group,the expression levels of TLR 4,MyD 88 and NF-κB mRNAs were markedly up-regulated in the area of PC 6 in the model group（P〈0.01）.Compared with the model group,the increased expression levels of TLR 4,MyD 88 and NF-κB mRNAs in the EA preconditioning group were significantly inhibited（P〈0.05）.No significant differences were found among the control,control＋EA and sham operation groups and between the model and sham EA groups in the expression levels of TLR 4,MyD 88 and NF-κB mRNAs（P〈0.05）.Conclusion EA preconditioning can improve myocardial ischemia and reduce the expression of TLR 4,MyD 88 and NF-κB mRNAs in PC 6 area of MIRI rats,suggesting an involvement of the regional cutaneous TLR 4/MyD 88/NF-κB signaling suppression in the initiation-transfer-amplification of EA stimulating signal inputs for relieving MIRI.